Hawaii Cooperative Extension Service

Transcription

1 Hawaii Cooperative Extension Service HO'RTICULTU'RE HITAHR College of Tropical Agriculture and Human Resources U. S. Department of Agriculture Cooperating 'DIGEST Department of Horticulture University of HawaII at Manoa In This Issue: FLOWER AND NURSERY INFORMATION No. 60, July 1981 TABLE OF CONTENTS Page Structuring the Day to Get More Done An Alternate Anthurium Cultural Method... 1 Nursery Notes... 3 Shading for Foliage... : Porous Concrete Available Publications... 7 Ten Ways to Kill Seedlings The Future of the Nursery Industry... 8 STRUCTURING THE DAY TO GET MORE DONE Common mistake: Focusing attention on whatever lands on the desk or whoever happens to drop in or call. That way, other people determine a manager's priorities, and his time is spent dealing with problems rather than opportunities. What to do: Make a list for the day in two columns. On the right, jot down meetings and appointments scheduled for specific times. On the left, list things to do in two sections. Upper part of the page is reserved for the important and urgent; if there are many important items, put a star next to the highest-priority items. Devote the lower part of the page to less important chores and items that can wait. How it works: On a good day, most of the top half of the page will be crossed off, some at the bottom left undone. That's okay. It means time was devoted to the priority items. AN ALTERNATE ANTHURIUM CULTURAL METHOD Foreign competition in anthurium flower production has increased to the point at which Hawaiian producers must take a good look at their own production methods. The Netherlands, for example, has reported a total of 160 acres of anthurium being produced under glasshouses. Other countries such as Jamaica, Costa Rica, Mexico, etc., are also reported to be producing anthuriums for cut flowers. Hawaii's competitive advantage in producing anthuriums is our ideal climate with minimum overhead cost and our advanced technological knowledge about producing anthuriums in Hawaii's environment. The key, then, in meeting our foreign competition is to increase our yields per unit area. This is important because establishment of an anthurium saranhouse nursery today costs approximately $40,000 to $50,000 per acre. Increasing the yield per unit area will in turn reduce the cost of producing an anthurium flower, thus enabling local growers to be competitive in the world market. The purpose of this article is to suggest to the anthurium industry a hypothetical, but workable anthurium cultural method, which incorporates results from experiments conducted by the University of Hawaii as well as methods presently being utilized by some innovative members of the industry. It is anticipated that this proposal will stimulate members of the industry to develop better and more efficient cultural methods for producing higher yields. The proposed method involves: I. Plastic pot or polyethylene culture. The anthurium plants will be planted in plastic pots or poly bags (Figure 1). A standard 3- or 4-gallon pot or bag will allow approximately 14,000 pots or bags per acre at three closely set rows of pots or bags with a 2' walkway between plots. Three matured anthurium plants will be planted in each pot or bag. This will allow a total of 42,000 plants per acre as compared to the standard bed practice of 25,000 plants per acre. Of major interest, of course, is the increase in theoretical yield (based on 4 marketable flowers per plant per year) from 8,333 dozens to 14,000 dozens per acre per year. The proposed medium consists of black cinder, topped with a dressing of fertilizer, COOPERATIVE EX,TENSION SERVICE 3050 MAILE WAY UNIVERSITY OF HAWAII. HONOLULU, HAWAII The UniverSity of HawaII at Manoa, College of Tropical Agriculture and Human Resources, Cooperative Extension Service and U. S. Department of Agriculture cooperating In presenting to the people of HawaII programs and services to Its citizens without regard to race, color, national origin, or sex. It Is an equal opportunity employer.

2 lime and nemacur and mulched with bagasse to hold moisture in the cinder. A minimum amount of medium will be used per pot or bag to allow replenishment of medium as the plants elongate. Ail irrigation system will be installed to keep the cinder medium moist at all times. Advantages of pot or bag culture include: l)good drainage and, therefore, reduction in the chances of contracting root rots caused by fungi such as Phytophthora or Phythium; 2) more efficient uptake of nutrients and protection against nematodes because the fertilizer, lime and nemacur are confined to the immediate vicinity of the roots; 3) a delay, to a certain extent, in the spreading of any soil-borne diseases from one plant to another; 4) the movability of plants without setback in growth; 5) earlier marketable flower production after planting, of nearly 3 months as reported by some users of pot or bag method; and 6) most importantly, an increase in the number of plants per unit area, thereby increasing the potential of II. producing more flowers per unit area. Leaf pruning: Of major concern in the pot or bag culture method with its increased plant population is a reduction of light due to the high density of plants, an increase in crooked flower stems, less control of insects and fungus diseases due to the decrease in penetration of pesticides, and reduction in water penetration to roots with overhead irrigation as plants increase in size. To overcome these factors, a new leaf pruning method will be used. This method was first suggested by Mr. Seigi Yogi, then tested by the University and is presently being utilized by several growers. All of the leaves will be pruned perpendicular to the leaf blade axis as shown in Figure 2. Approximately Y2 of the leaf blade will be pruned. Pruning will be done after one year of normal growth to allow the firm establishment of the plants during their early stages of growth. This method will negate the concerns expressed earlier of high density planting in pots or bags. Figure 1. Plastic pot culture of anthuriums grown for cut flowers at Floral Resources, Hawaii, Waiakea, Hawaii. 2

3 Figure 2. New anthurium leaf pruning method shown utilized at Green Point Nursery, Hilo, Hawaii. In summary, anthurium plantings in pots or bags are advocated to increase plant population per unit area and thereby, increase yield, as compared to the present bed method. A new leaf pruning method is also advocated to overcome the undesirable effects of increased plant density. Tadashi Higaki, Horticulturist Joanne Imamura, Research Associate NURSERY NOTES Weed Whackers May Injure Young Trees From Connecticut comes a report that injury to the base of young trees has been noticed with increasing frequency from the use of weed whacker type nylon filament trimmers. Total girdling of young thin-bark trees can result very quickly from the careless use of this type of weeding/edging equipment. This type of weeding/edging equipment can make weeding and edging less <i' chore but take care when using it around newly planted trees and shrubs. Plants and the Landscape Vol.l, No.3, July 1980 Local Nurseryman Makes News Richard Garcia, who with his father, Labriano, owns The Plant Jungle in Honolulu, Hawaii, was the subject of a half page feature article in the Honolulu Star Bulletin in December. At 32, Garcia has just concluded 10 years as a State Representative in Hawaii. At the time he was first elected he was the youngest representative ever elected to the Hawaii legislature. Garcia's business includes a wholesale plant nursery, specializing in areca palms, a plant rental operation, and a' florist shop in Grosvenor Center. The palm operation includes two shade houses of 1.7 and 2.7 acres to acclimate the plants to indoor use. In 1981, he expects to add a 7-acre shade tent, which he says will make him the largest grower of areca palms in the country. Once the third shade tent is in operation, plans call for an annual gross of $2.5 million, according to Garcia. Pacific Coast Nurseryman and Garden Supply Dealer February,

4 Depreciation Switch If you use accelerated depreciation, you should periodically detennine whether you would be better off switching to the straightline method. Here are three situations where such a switch might be advantageous: (1) When it would produce larger deductions beginning in the seventh year of a 10-year useful life span, or the 12th year of a 20- year useful life span. (2) When it would defer the larger deductions in a low-profit year to future high-profit years. (3) When it would result in additional taxable income that can be used to offset an expiring operating loss carry-over. Tax Prompter Crop Insurance Amendment Covers Nurseries The Federal crop insurance program has been amended to cover nursery crops. The amendment was requested by the American Association of Nurserymen and introduced by Representatives Panetta and Coehlo (D-Calif.). Under the provisions of the act, participation in a program is voluntary, and the Federal Government will pay 30 of up to 65 percent of nonnal crop yield. Weeds, Trees & Turf March 1981 Soil Miracle Products Evaluated These products, often called soil activators or soil conditioners, supposedly provide some beneficial soil effect, usually through addition or stimulation of soil microorganisms, or by the addition of some mysterious chemical extract that will result in increased yields. Concern about the validity of these materials and a lack of scientific data to support any opinions, promoted this study. Two of the products-medina and Supernate-were evaluated. Laboratory analysis indicated that the amounts of nutrient elements that would be added to the soil, based on manufacturers' recommendations, were very low in relation to crop nutrient requirements. Application of these products at recommended rates did not 4 alter the number or activity of microorganisms that were naturally present in soils. E. P. Dunigan and O. D. Curtis News and Views Vol. 21(2),1979 R&D RESEARCH AND DEVELOPMENT (R & D) is a function of most manufacturers (producers). The financial support of an agricultural experiment station is part of this activity, but, in addition, each greenhouse should carry on some testing, comparison, investigation and experimentation. How much space and time to devote to this activity may be estimated by setting aside a 5 to 10 percent dollar value as a cost of sales or cost of production. This can then be appropriated toward greenhouse space and contributions to reach at some institution. What you do at your place is your own, whereas an institution will have to share the results with other contributors. This is not all bad, however, because contributions are often "seed money" that helps to generate a much larger research fund for quicker and more farreaching results. Florist Review May 7, 1981 Trucking Deregulation Bill is Passed A trucking deregulation act makes it easier to obtain certification by the Interstate Commerce Commission. The act retains agricultural exemption (which includes nursery stock) and also eliminates the gateway requirements and circuitous route limitations imposed on motor carriers. Carriers now are pennitted to carry mix.ed loads of both regulated and exempt commodities. Nursery stock may still be transported by nonregulated carriers. AAN Traffic Consultants have published a booklet entitled "Trucking Deregulation: How Far It Actually Goes," available from Bohman Industrial Traffic consultants, 335 East Broadway, Gardner, MA Weeds, Trees & Turf March 1981 Evaluation of Root Growth in Varying Medium Densities and Through Dissimilar Soil Surfaces The roots of trees and shrubs that are transplanted into heavy textured soil and backfilled with porous, low bulk density media often

5 fail to extend beyond the adjacent backfill and into the undisturbed, surrounding soil. The reported study was designed to evaluate root growth and penetration through media of varying densities and across dissimilar soil surfaces. The number of roots that penetrated through the medium immediately. surrounding the roots and into the surrounding high density mineral soil into which the plant root ball was transplanted was greater when the density of the medium immediately surrounding the roots was greatest... the number of roots that penetrated through the interior medium and into the high density soil was significantly reduced by a flazed, smooth interface surface. Ralph T. Nicolosi & Thomas A. Fretz HortScience Vol. 15(5), October, 1980 SHADING FOR FOLIAGE The recently published Foliage Plant Production (3) recommends desirable average light intensity levels for production of potted foliage plants (Table O. The supporting research was carried out in Florida. Often the amount of shade is expressed as 30% saran shade or 70% Table 1. Suggested light intensity levels for production of some potted acclimatized foliage plants. Botanical name Aqlaonema spp. Aphelandra squarrosa Araucaria heterophylla Asparagus spp. Brassaia spp. Calathea spp. Chamaedorea elegans Chamaedorea erumpens Chrysalidocarpus lutescens Codiaeum variegatum Cordyline terminalis Dizygotheca kerchoveana Dieffenbachia spp. Dracaena deremensis (cultivars) Dracaena fragrans (cui tivars) Dracaena marginata Dracaena -others Epipremnum aureum Ficus benjamina Ficus elastica (cultivars) Ficus lyrata Maranta spp. Monstera deliciosa Nephrolepis exaltata (cultivars) Peperomia spp. Philodendron Selloum Philodendron spp. Pilea spp. Sansevieria spp. Schlumbergera truncata Spathiphyllum spp. Syngonium podophyllum Yucca elephantipes Light intensity (foot-candles)

6 Table 2. Percent shade cloth needed to obtain desired light intensity levels (ft-c). (Select shade cloth percent nearest to desired foot-candle level.) Foot-Candles desired Florida Summer Winter Hawaii Florida Hawaii 1, , , , , , , , , , , , , ,000 saran shade. This does not translate easily to the foot-candle method of measuring light intensity as we are not able to tell what is full light intensity. With the publication (1) of the percent shade cloth needed to obtain a desired light intensity (foot-candle) in Florida, it is appropriate to provide a similar comparison for Hawaii where full light intensity is somewhat greater than in Florida (Table 2). Florida's summer maximum is approximately 13,000 ft~c while Hawaii's is 14,000. Florida's winter maximum is 11,000 ft-c and Hawaii's is 12,000. Hawaii light readings were recorded with a Weston Sunlight Illuminator Model 756 at midday on clear sunny days in June and December. Calculations in Table 2 are based on the full light intensity readings at these times. Table 2 tells us that we need 2 to 4 percent more shade than Florida during summer to achieve the same light intensity at the levels recommended for potted foliage plants and 3 to 8 percent more during the winter. Further, Hawaii needs to adjust shading less at these light intensities during winter than does Floririda. One problem is that plants "perceive" light in terms of the energy it provides for photosynthesis rather than in terms of the foot-candle units of illuminance. Within the visible spectrum of Ugh t used in photosyn thesis, not all wavelengths (colors) of light are equal in their efficiency in photosynthesis. We do not know just how saran shading alters the proportions of say, red and blue light, with the different seasons of the year in Hawaii. Research conducted in more northerly areas tells us that there is relatively more red light in proportion to far red in summer than in winter, but we do not know how or if this proportion changes as a result of saran shading. The importance of these considerations is related to the effect red light has on internode length and number of breaks, shortening the first and increasing the second while far-red light has opposite effects (2). References 1. Conover, C. A. and R. T. Poole Selection of shade levels for foliage plant production as influenced by fertilizer and temperature. Minnesota Florists Bulletin 30 (1): Healy, W. H. and H. F. Wilkins Light Roses. Minnesota Florists Bulletin 30 (1): Joiner, J. N., C. A. Conover, and R. T. Poole Nutrition and Fertilization. Chapter 9. IN Foliage Plant Production. J. N. Joiner, 6

7 Ed. Prentice-Hall, Inc., N. J. Richard A. Criley Horticulturist POROUS CONCRETE Porous concrete makes a very good floor surface for greenhouses because it allows water to pass through and avoids the puddles or standing water common to floors of regular concrete, sand or gravel. Porous concrete is made from a uniformly graded aggregate and a cement water paste. It was first used in greenhouses in England with the idea brought to the U. S. by Professor Jim Rathmell of Penn State University. A series of tests to determine usable water/ cement and cement/aggregate ratios and the effects freeze-thaw cycles was conducted at Penn State University. Test results were used as a basis for recommendations for mixing, placing and curing porous concrete in floors, walkways, display areas, patios, etc. The most satisfactory mix contains one cubic year or 2800 Ibs. of 3/8 inch diameter stone, free of dust and uniform in size, 5.5 sacks of standard Portland cement and 4.25 gallons of water per sack of cement. There is no sand in the mix. The mix is placed on a well drained base of sand or gravel. A 4-inch thick floor will carry personnel and light vehicle traffic. The concrete should be moved as little as possible during placing, screeded to the final grade with no tamping as it will consolidate the mix and close the pores. Use overhead concrete bucket, two-wheel concrete buggy or wheelbarrow to move concrete to the floor location. The surface is not trowel finished. The final surface will be rough compared with regular concrete but it is comfortable for walking and vehicles maneuver easily on it. When the floor has been screeded to the final level, cover with a 4 mil polyethylene film to keep evaporation loss to a minimum and allow the concrete to cure for at least one week before using the floor. Roll on top of the PE film with a lawn roller to produce a relatively smooth surface. The final product should have a load carrying capacity of about 600 Ibs. per square inch of surface. Average Portland cement concrete (regular concrete) can carry about 2500 Ibs. per square inch of surface. Therefore, the use of porous concrete should be restricted to areas where personnel or light vehicles such as garden or utility tractors operate. Porous concrete should not be used in soil mixing areas or where large quantities of small particles can fall onto the floor. The particles will clog the pores and prevent downward water movement. R. A. Aldrich Connecticut Greenhouse Newsletter March 1981, No. 104 A V AILABLE PUBLICATIONS Several new publications have recently been released by the College of Tropical Agriculture and Human Resources of the University of Hawaii. Copies may be obtained from your local County Extension Office or by writing to the Publication and Information Office, Rm. 107, Krauss Hall, 2500 Dole St., University of Hawaii, Honolulu, HI Ornamentals Short Course Proceedings The proceedings of the Second Annual Ornamentals Short Course, Res. Ext. Series 003, by F. D. Rauch and K. W. Leonhardt is available. This report contains papers presented at the conference. Turfgrass Recommendations This publication, 1981 U. H. Recommendations for Turfgrass, HIT AHR Brief 001, by C. L. Murdoch et al., contains turf recommendations for establishment and maintenance, nematode control, insect control, disease control and weed control. Simple Orchid Culture Circular 452, Simple Orchid Culture, has been revised and reprinted by K. W. Leonhardt. This publication contains cultural information on the various types of orchids grown in Hawaii along with a guide for the control of the various orchid pests. Home Gardening Two new additions to the Instant Information, General Home Garden Series by Wade W. McCall are: No. 28 Treatment for Control of Soil Organisms No. 29 Site Selection for the Home Garden Compendium of Fungicides The publication is a listing of the various host plants, the disease causal agent and the chemicals available for control. The 67 page bulletin was prepared by Albert P. Martinez, Plant Pathology Specialist. 7

8 TEN WAYS TO KILL SEEDLINGS So you want to kill your seedlings? Perhaps you think you make too much income, pay too many taxes, or would like to close shop and go on unemployment. There are several easy ways to kill your seedlings this winter to insure that you won't have a bedding plant to sell next spring. They are: 1. Buy your seed one to four years in advance and then don't store it properly, keeping it on top of the boiler or in an area of high humidity. 2. Maintain poor sanitation, and encourage mice, rodents and disease to move into the greenhouse. 3. Use a heavy soil mixture, staying away from artificial mixes. 4. Don't test your growing media, but instead guess if you might be short on one of the essential nutrients or have a ph too low or too high. 5. Handle the seedlings roughly and transplant them too deep. Sow seeds as thick as you can and handle the seedlings by their stems. 6. Don't fertilizer at all, or feed very heavily. Never apply trace elements. 7. Spray herbicides on the pipes, and don't read the directions on the insecticide bottles. 8. Don't water at all, or water very heavily, preferable in the late afternoon. 9. Provide as little ventilation as possible, and don't let fresh air into the greenhouse. 10. Don't harden seedlings off before transplanting, but instead leave them in the germination house so they can stretch, be soft and grow as large as possible. Adapted from a presentation made by Ken Ludwig, Vaughn-Jacklin, Inc., at the Bedding Plants Inc. Conference, October 1979 NYSFIB No. 112, January 1980 predictions for the future by drawing a profile of future customers for the nursery industry. Those customers, he said, will have a greater awareness of waste, energy and environment; be more involved with nature; desire greater elegance and personalization; have a more casual life style; desire greater novelty and change; desire instant gratification; show continued growth in women's careers; and show a rise in consumerism and demand for value. "It is important to understand who is going to be in the marketplace," Mariani said, "because their desires are going to dictate our needs." Mariani also listed a number of internal changes which he feels are essential to the success of the nursery industry, including: More professionalism in industry; Better plantings; More profitability in all aspects of business; Better management of inventories; Better money management; Better match of services to demands; More effective advertising; More effective dealings with government; and More creativity with research and development. With regard to the nursery business, Mariani predicted a strong future. Adopted from report in Voice of MAN March-April,1981 FOOD FOR THOUGHT Against stupidity the gods themselves fight in vain. Johann Schiller ( ) The fact that boys are allowed to exist at all is evidence of a remarkable Christian forbearance among men. Ambrose Bierce ( ) THE FUTURE OF THE NURSERY INDUSTRY Gary Mariani, Corporate Vice President for Weyerhaeuser Corporation, discussed "The Future of the Nursery Industry" at the 59th Annual Convention of the Michigan Association of Nurserymen, Weyerhaeuser, a wood products firm, extended into the nursery business in the early 1970's. I Mariani showed some of Weyerhaeuser's 8 NOTE: The use of trade names is for the convenience of readers only and does not constitute an endorsement of these products by the University of Hawaii, the CoUege of Tropical Agriculture and Human Resources, the Hawaii Cooperativ"l Extension Service, and their employees. Extension Specialist in Horticulture